Since the mid-1990's, when the O.J. Simpson murder trial in Los Angeles introduced the concept of DNA evidence to the public, it has become the "gold standard" of forensic tools - evidence considered so reliable that few question its results.

And it's not just used to convict criminals. Often it's used to set them free. Results of DNA tests have already led to the exoneration of more than 200 prisoners, almost all convicted of the serious crimes of rape or murder.

Now, suddenly comes an Israeli company ready to upset the apple cart with its claim that a lab can create artificial DNA and "engineer a crime scene."

Officials at the company, Nucleix, based in Tel Aviv, say they were able to successfully "create" fake DNA by taking a blood sample from one woman, removing the white blood cells that contain her DNA and replacing them with cells containing a man's DNA, collected from his hair.

The implications, according to those at Nucleix, are enormous and frightening: imagine an unscrupulous lab technician who could implicate an innocent person in a crime; or a bad cop who could plant DNA evidence to convict a suspect.

This new development is and should be worrisome to anyone who cares about fairness in the American judicial system. Jurors rarely question the validity of DNA evidence introduced at trial.

However, read the article a little closer and you discover what this new development is also about: making money.

Nucleix has done more than just create "fake" DNA. The company has also constructed a test to ferret out that artificial DNA, a test which it hopes to sell to forensic labs.

(iStockphoto)

The announcement that DNA can be faked has already been greeted with disdain by some DNA experts. Rock Harmon, a former Alameda County, Calif., deputy district attorney, dismissed it as simply "a sales pitch for a new product."

Still, from the perspective of someone who covers murder trials regularly involving DNA evidence, I am intrigued by this latest development.

What Nucleix has done is just confirm a fact that is often overlooked: DNA test results are only as reliable as the people who collect the genetic material and then later analyze it in the lab. When done properly, DNA evidence is the "gold standard" of forensic tools, but whenever humans are involved, there is always room for error, and, yes, unscrupulous behavior. The company's "fake" DNA just reminds us of that fact.

Until now, there has been little a defense attorney could do to raise questions and doubts about DNA evidence. In a handful of cases, including one we have followed here at 48 Hours Mystery involving the murder convictions of Kevin Cooper, defense attorneys have asked the courts to have incriminating DNA samples tested for a certain preservative known as EDTA. The presence of EDTA, say defense attorneys, is proof that a defendant's DNA had been kept in the lab and then later planted as evidence to secure his conviction.

The only problem is that EDTA, a common preservative, is often found in the environment, particularly in detergents. So the question becomes: is the amount of EDTA found in the sample so high that it proves conclusively that the DNA was planted? So far, that answer has been 'no.' As far as I know, no defense attorney has successfully been able to prove by EDTA levels that DNA evidence had been planted.

This new test that allegedly distinguishes "fake" DNA simply gives defense attorneys a new tool to question DNA evidence. And it's that "questioning" of even the so-called "gold standards" that I welcome.

On that point, I am sure Portland, Ore., attorney Brandon Mayfield would agree. On May 7, 2004, Mayfield was arrested for participating in the train bombing in Madrid, Spain earlier that year that had killed 191 people and injured thousands of others.

The FBI had no doubts about Mayfield's guilt; after all, two of the best FBI fingerprint analysts had used the "gold standard forensic tool" to identify his prints on evidence collected at the crime scene. The only problem was these experts were wrong. As it turns out, Mayfield's fingerprints were very similar to those of another man - a known terrorist - who was later identified and picked up by Spanish investigators.

If not for the Spanish investigators, the very innocent Brandon Mayfield might still be in prison today.

So much for invincible "gold standards!!"

Erin Moriarty is an award-winning correspondent for CBS News and has been with 48 Hours since 1990. Drawing on her training as an attorney, she has examined some of the most important issues of the day, including DNA testing in death-row cases, the abortion controversy and battered women's syndrome. She covered the Oklahoma City bombing, the Columbine High School shootings and the 9/11 investigation overseas. Moriarty has won nine national Emmy Awards and a 2001 Press Club Award, among others.